Exit ducts of annular reverse flow combustors configured for sliding engagement with a downstream turbine vane ring, such that at least axial relative movement therebetween is possible, are typically expensive to manufacture. Constructing the combustor walls and exit duct section using sheet metal reduces the material cost, however the manufacture of such a sliding-type joint made of sheet metal nonetheless involves several time consuming, and therefore costly, manufacturing operations. As opportunities for reducing cost and improving cost effectiveness are continuously sought, there remains a need for an improved combustor construction to further reduce manufacturing cost.